What is the most likely cause of a certificate error on a new web server using a wildcard SSL certificate?

A certificate error on a new web server using a wildcard SSL certificate is most likely due to a misconfiguration in the certificate itself or in relation to its deployment on the server. Wildcard SSL certificates are designed to secure multiple subdomains under a single domain (for example, *.example.com), but if the certificate is not set up correctly—such as if it does not correctly match the subdomain being accessed, or if the server is not properly configured to use the certificate—it will result in an error when users attempt to access the website.

Configuration issues can arise from various factors, such as an incorrect certificate installation, problems with the server's SSL settings, or the use of an unsupported server configuration. It's important to ensure that the server is properly recognizing and utilizing the wildcard certificate to avoid these errors.

Other possible causes, like an expired or revoked certificate, would also cause issues, but these situations are less likely on a new web server with a newly issued wildcard SSL certificate. The option regarding the certificate not being signed would typically result in a more fundamental trust issue that would not specifically relate to the usage of a wildcard certificate. Therefore, misconfiguration stands out as the most probable cause of the error in this context.